As you know, the Application Cache helps you run your web app offline, significantly speeds up startup time, and reduces bandwidth bills. All good things to the HTML5 developer!
However, for large apps and sites, it can be cumbersome to add each and every file required for the App Cache. Luckily, there are now tools that can help you auto-generate your App Cache manifest.
Some options include:
Give them a shot, let us know in the comments how they work for you.